Rheostat



Febf 23 1926.,

Q. STERN ET AL.v

RHEOSTAT Filed Dec. 5, 1924 24 IW mmnnunif,

INVENTORS ATTORNEY reame Feb. 23.1926..

UNITED sTATEs 1,574,521' PATENT erstes. f

cHARLnssTERN Ann DAvTD BROWN, or. NEW Yoan, n. Y.

RHEOSTAT.

p Application iled December 5, 1924. Serial No. 754,196.

To all whom t may concern:

Be it known that we, CHARLES STERN and DAVID BnowN, citizens of the United States, and residents of Manhattan, in the county o'f New York and State of New4 York {whose'post-ofiice addressesv are, respectively, 204 West 108th St., New York city, and 1432 University Ave., New York city), have invented certain new and useful lmprovep member 14.

ments in Rheostats, of which lthe following is a specification.

@ur invention relates to rheostats suitable for a variety of purposes, but especially adaptable for use in radio sets; and it has Jfor its object to provide adconstruction embodying a simple, convenient and positive means of making and retainingr contact of the movable contact member with the vresistanee element. Further objects will appear from the description hereinafter given: ln the accompanying drawings, Figure 1 is a plan view of the 'rheostat; Figure 2 is a sectional elevation on the line A-'A of Fig. 1^; Figure 3 is an elevation of another form of the invention, part of' the base being shown broken away; and Figure 4 is an elevation showing another possible arrangement of some of the parts of this improvedrheostat.

- Referring tothe drawings, 1 is the base of the rheostat made of insulating' material,

. and 2 is the panel, saidpbaseland panel each containing a hole adapted to` receive the externally threaded supporting member 3. The said supporting member shown has a cylindrical hole of one diameter extending into a bore of a greater diameter, forming an annular abutment o r stop 4. The hollow sleeve 5 ts within member 3, and contains an expanded portion or collar 6, and a pin 7 placed transversely through it as shown.V The shaft'8 is split at one end, and inserted into the sleeve' in such manner that the prongs 9 and 10 are separated by said pin `7. The other end 11 `of saidv shaft is suitably secured to the knob 12. Attached to the.

sleeve 5 is a connecting -member 13 suitably secured to :the contact member 14. This contact member consists of a casing 15 having an open-ended cylindrical bore with an abutment 16, and a contact piston 17 at one l -end of which is a contact point.18,'thejotl1er end 19 beingswedged'and protruding outass - side of said casing. A. helical spring 20 is v placed on said piston ,and positioned be- '19 prevents the piston from tween the abutment 16 and av shoulder 21 on the piston. h

The base 2 is grooved to accommodate the flexible insulating strip 22iaroundrwhichf is wound the resistance wire 23. The perforated posts 24 and 25 are secured by set screws as shown, and are adapted-to serve as binding posts for the ends of the resistance wire, and as stops for the Contact lVhen the knob 12 is turned, the prongs 9 and 10 of the shaft 8, in engagement with the-pin 7, will Aactuate said sleeve 5 to rotate' within the said supporting member 3 in the direction of the knob. rlhis motion will be transmitted by the arm 13 to the contact 'member 1 4, causing anv arcuate movement of the contact over the resistance wire. The spring 20, bearing down upon the shoulder 21(0f said piston, will keep the point 18 inconstant contact with the re' sistance wire 23. The spring is kept in its position within the casing by the abutment, 16 and the Shoulder 21. `The swedg'ed end going through the bore in casing 15.

The collar 6 abutting against the stop Il,

'sets a limitto the linear movement of the sleeve 5 in the direction of its longitudinal axis,` thus preventing said sleeve from re. moving the contact member from its engagement with the resistance element. The position of the stop 4 with respect to the ContactV point 18 can be adjusted by turning the, externally threaded supporting member 3 within the internally vthreaded holes in panel 2 and base 1, causing a linear adjustment of said member 3 in the direction of its longitudinal axis. Thus the pressure of th contact point 18 against the resistance wire 23 can lbe regulated and adjusted. 1

Figure 3 shows a construction wherein the aforementioned sleeve is entirely eliminated, the shaft 26 containing an expanded portion 27 free for rotary and linear movement within the supporting member 28. The smaller end 29 of this shaft lis attached to the Icontact member 30, the other end 31 being suitably secured to aknob 32.

The supporting member 28 is externally threaded, and mounted thereon aretwo nuts, 33 and 34. These nuts bear against the base 35 and the panel 36, as shown, serving to lockthem into positionfwith the supporting struction is that it constitutes a one-hole member28. This arrangement is adaptable for use with panels offvarious thicknesses, as the position of ,these nuts on the supporting member c'anrbe adjusted to suit the conditions.v Another feature of this conmounting, that is,- a construction -wherein only one hole need be drilled into the panel to secure the rheostat to the panel. The

supporting member 28 in conjunction with thenuts 33 and V34 is sufficient vsupport as a mounting, thus obviating the necessity of drilling additional holes inthe panel for` attachment'to the base of therheostat.

Figure 4 indicates another possible construction, where the shaft is split; as in F ig.

' arm 41'.

1, the split end 37, however, being-adapted for attachment to the knob 38 by engaging the pin 39, the other end 40 being adapted forattachment to the contact Iactuating What we claim is:

1. A rheostat comprising abasemember of insulating material; a resistance wire wound around a suitably positioned .insulating strip; a hollow tubular supporting memu` ber suitably secured tol saidbase and containing integral with itself an internal annular abutment or stop; al hollow,'cy1indiical sleeve with an annular collar and containing' a diametral pin transversely positioned with respect to the vlongitudinal axis o f said sleeve; said sleeve being free for linear and rotary 'movement' vwithin said j supporting member, and-said. collar' being adapted to abut againstsaid'annular stop; a

` shaft with a slot at one end adapted to engage said pin, theotherend of theshaft being adapted for attachment toa knob;'a

contact member movable over| an arcuate path and comprising a hollow casing, a contact piston containedwithin said casing and free to move therein,` one end of said piston serving as a contact point; a spring within said casing ada ted toy actuate said piston the direction o saidresis'tance wire, and to' -hold said contact point in co-operation withl said resistance element; means for connect- A ,of insulating'material; ai' resistance wire wound around a suitably positionedinsulat- `ing strip a hollow `tubulai-su porting mein bei` suitably' secured to said ase and con-.

taining lintegral' with itself an internal anl nular labutment or .-stop;l a shaft positioned within said supporting member,- said shaft `being freeA for linear and rotary'morvement i' within said supporting member; a knob suitably secured to one end of said shaft; a contact member movable over an arcuate 'path and comprising ahollow casing, a contact pis-- .comprising a hollow casing, a contact ton contained within said casing and rec gy said shaft withv said contact member y and contact stops on said base.

v. 2. A rheostat comprising .a member ton contained within said casing and free move therein, one end of said piston serving as a contact point; a spring within said casing adapted to actuate said pistonin the direction of said resistance wire, and to hold said tain said shaft with said collar; said shaftv being positioned within said supporting member so as to permit of the linear and rotary movement of the said shaft; said 'supporting member. being placed within suitably placedhol'es in said base and in a suitably positioned panel board; a contact member movable over an arcuate path and to move therein, one end of said piston serving as acontact point; a spring within said 'casingfadapted-toactuate said piston in the direction of said'resistance wire, and to hold said Contact point in cooperationwith said resistance element; means for connecting said shaft with said contact member; and

ylimiting contact stops on said base.

4. A. rheostat comprising a base member.

of insulating material; a resistance wire wound around a suitably positioned insulating strip; ay hollow, tubular supportin .member suitably secured to said base an containing integral with itself an internal` annular stop; a shaft positioned within said supporting member; said shaft having an annular collar on its lateral surface, said collar being ada ted to abutagainst said annular stop; a nob adaptable for attachment tov one end of said shaft; a contact comprising a hollow casing, acontact piston 'v contained within said casng and free to move therein, one end of said piston serving as a contact point; a sprin within said casing adapted to actiiate sai piston in the direction of said resistance wire, and to hold said contactpoint -in co-operaton with said resistance element; means `:for connectin said shaft ywith said Alimiting contact'stops on said base.

In testimony whereof we ax our sgnar 1 leliminas efraim.i Y

,DAVIDv BROWN.A p

1'10 member movable over an arcuate .path and contact member; an .12 

